Identification of α-Glucosidase Inhibitors from Leaf Extract of Pepper (Capsicum spp.) through Metabolomic Analysis.

Metabolomics and in vitro α-glucosidase inhibitory (AGI) activities of pepper leaves were used to identify bioactive compounds and select genotypes for the management of type 2 diabetes mellitus (T2DM). Targeted metabolite analysis using UPLC-DAD-QToF-MS was employed and identified compounds that belong to flavone and hydroxycinnamic acid derivatives from extracts of pepper leaves. A total of 21 metabolites were detected from 155 samples and identified based on MS fragmentations, retention time, UV absorbance, and previous reports. Apigenin-O-(malonyl) hexoside, luteolin-O-(malonyl) hexoside, and chrysoeriol-O-(malonyl) hexoside were identified for the first time from pepper leaves. Pepper genotypes showed a huge variation in their inhibitory activity against α-glucosidase enzyme(AGE) ranging from 17% to 79%. Genotype GP38 with inhibitory activity of 79% was found to be more potent than the positive control acarbose (70.8%.). Orthogonal partial least square (OPLS) analyses were conducted for the prediction of the AGI activities of pepper leaves based on their metabolite composition. Compounds that contributed the most to the bioactivity prediction model (VIP >1.5), showed a strong inhibitory potency. Caffeoyl-putrescine was found to show a stronger inhibitory potency (IC50 = 145 µM) compared to acarbose (IC50 = 197 µM). The chemometric procedure combined with high-throughput AGI screening was effective in selecting polyphenols of pepper leaf for T2DM management.

Anti-Obesity Effects of Petasites japonicus (Meowi) Ethanol Extract on RAW 264.7 Macrophages and 3T3-L1 Adipocytes and Its Characterization of Polyphenolic Compounds.

Koreans have been consuming Petasites Japonicus (PJ) as food. Although the therapeutic effect of PJ on allergic or inflammatory reactions associated with asthma has been proven, its effect on obesity is unclear. Therefore, the present study was aimed to assess the obesity related anti-inflammatory and anti-adipogenic effects of ethanol extract PJ (EPJ) on the inflammatory response in RAW 264.7 macrophages and on differentiation in 3T3-L1 adipocytes. In addition, the polyphenolic compound was quantitatively characterized from the EPJ using ultra performance liquid chromatography coupled with diode array detector, quadrupole time-of-flight-mass spectrometry (UPLC-DAD-QToF-MS). In RAW 264.7 or 3T3-L1, reduction of nitric oxide (in macrophages) production as well as monocyte chemoattractant protein-1 and tumor necrosis factor-α were observed. Treatment of EPJ in adipocyte differentiation showed an improvement in adiponectin and lipid accumulation and a significant reduction of PPARγ and FABP-4 mRNA expression levels. On the other hand, mRNA expression of UCP-1, PPARα, and ACO increased in the EPJ treated group. In addition, a total of 26 polyphenolic compounds were detected and of which 12 are reported for the first time from PJ. The higher content of diverse polyphenolic compounds presented in EPJ might be responsible for the observed anti-inflammatory and anti-adipogenic effect. These results suggest that PJ is valuable in improving obesity-related inflammatory responses.

Comprehensive characterization of hydroxycinnamoyl derivatives in green and roasted coffee beans: A new group of methyl hydroxycinnamoyl quinate.

The aim of this study was to quantitatively characterize 19 green and roasted coffee beans by ultra-performance liquid chromatography coupled with diode array detector and quadrupole time-of-flight mass spectrometry. A total of 57 phenolic acids including nine methyl ester of mono-, di-caffeoylquinic acid, and feruloylquinic acid were identified. The methyl hydroxycinnamoyl quinates are reported for the first time from Coffea arabica and Coffea robusta. The total phenolic content ranged from 5628 ±â€¯227 to 8581 ±â€¯109 mg/100 g dry weight (DW) in green, and from 791 ±â€¯63 to 1891 ±â€¯37 mg/100 g DW roasted beans. The methyl caffeoylquinates accounted for 2.1% of the total phenolic acids. The result suggested that the phenolic composition was affected by the type of species, cultivars, and roasting process. Hence, to retain the balance between health beneficial phenolics and sensory attributes, optimization of roasting condition specific to the cultivar type substantially required.

In vitro antimicrobial and antioxidant activities of anthrone and chromone from the latex of Aloe harlana Reynolds.

In the search for new antimicrobial and antioxidant compounds from plants, the latex of the medicinal plant Aloe harlana Reynolds from Ethiopia was subjected to bioassay-guided fractionation, which led to the isolation of two known compounds, anthrone (aloin) and chromone (7-O-methylaloeresin A). The latex and its two constituents were assessed for their possible antimicrobial activities against 23 bacterial and four fungal strains using the disc diffusion method and their antioxidant activity by two complementary test systems, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2-deoxyribose degradation assay methods. The isolated compounds showed promising results against various pathogenic bacterial and fungal strains in comparison with standard drugs. Moreover, 7-O-methylaloeresin A exhibited good activity against multiple drug resistant Staphylococcus aureus (NCTC 11994) and Salmonella typhimurium (ATCC 1255) with MIC values of 0.72 and 0.18 mm, respectively. Among the fungal strains tested, Candida albicans (ATCC 10231) was the most susceptible organism to the latex and the two isolated compounds. The latex and isolated compounds also showed significant activities on both antioxidant assays with the highest activity being observed for 7-O-methylaloeresin A, which gave IC(50) values of 0.026 mm and 0.021 mm for DPPH and 2-deoxyribose degradation assay, respectively. These findings support the traditional uses of the plant for the treatment of various infectious and inflammatory diseases.